1. Field of the Invention
The present invention relates to an operating mechanism for operating a multi-pole circuit breaker assembly, such as a medium voltage switchgear, comprising for each circuit breaker in the multi-pole circuit breaker assembly:    a connection assembly for connection to an operating shaft of the circuit breaker, an actuator for changing between an ON and OFF state of the operating mechanism, a translation assembly for transferring a movement of the actuator to the connection assembly, and a compression spring exerting a force on the operating shaft in the ON state of the operating mechanism the force exerted by the compression spring being adjustable by a force setting assembly in a continuous manner.
2. Background Information
Japanese patent publication JP-11-040013 describes an operating mechanism for a multi-pole circuit breaker. A connection is made between a swinging arm 4 and a link rod 60, using an elongated hole 65, pin 66 and pressure spring 6. The contact force seems to be adjustable using screws and bolts 61a-c in a continuous manner (using a screw thread).
Japanese patent application JP 9-161629 discloses a drive force transmitting device for use in co-operation with a circuit breaker. Two springs are provided, and the stroke can be adjusted using a hexagonal eccentric roller. The adjustment takes place with an opened electrode of the circuit breaker by rotation of the eccentric roller.